The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Prosthetic joints can reduce pain due to arthritis, deterioration, deformation, and the like. For instance, hip joint prosthetic assemblies often include femoral components (i.e., components attached to a resected femur) and pelvic components (i.e., components attached to a pelvis), and the femoral components are movably coupled to the pelvic components to replicate the mechanics of the anatomical hip joint. More specifically, pelvic components of a hip joint prosthetic assembly can include a shell and a liner. The shell fixes to the patient's pelvis, within the acetabulum, and the shell receives the liner. The liner fixes to the shell and is coupled to a head of the femoral component of the prosthesis. Accordingly, the liner receives the head of the femoral component, and the head articulates on an inner surface of the liner.
Oftentimes, the shell and liner are secured against relative rotational movement by a taper lock. Furthermore, in some assemblies, the shell and liner are retained using a ring lock feature. Specifically, a ring member affixes to one or both of the shell and the liner and interferes with movement of the liner axially away from and out of the shell. Additionally, some prosthesis assemblies include a polymeric inner member disposed between the shell and the liner. The inner member covers the outer surface of the liner and can resiliently flex when being inserted into the shell to provide an adequate fit.